Manmade Debris Found in 1 in 4 Fish Sold in California Markets, Study Finds

Researchers at the University of California, Davis, have discovered that a highly alarming percentage of fish at markets in California and Indonesia are contaminated with manmade debris. Their findings, published by Scientific Reports on Wednesday, suggest that 25% of fish sold at fish markets contain plastic or fibrous minerals.

To conduct the study, researchers at U.C. Davis teamed up with Hasanuddin University in Indonesia. Researchers tested 64 fish at markets in Half Moon Bay and Princeton, California, and 76 fish from markets in Makassar, Indonesia. A quarter of the fish in both sample groups were found to have plastic or fibrous debris present in their digestive systems.

The type of anthropogenic debris varied by region, according to the findings. In Indonesia, 100% of the debris found in contaminated fish was plastic. Of the contaminated fish in California, fibrous materials made up 80% of the manmade debris.

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"It's interesting that there isn't a big difference in the amount of debris in the fish from each location, but in the type—plastic or fiber," said lead author Chelsea Rochman, a postdoctoral fellow at the U.C. Davis School of Veterinary Medicine, Phys.org reports. "We think the type of debris in the fish is driven by differences in local waste management."

The recent findings further prove that the pollution and dwindling of our food supply is a growing concern, according to a 2014 study from the Massachusetts Institute of Technology.

"The ubiquity of anthropogenic marine debris and the toxicity of chemicals associated with the material have begun to raise concerns regarding how the ingestion of anthropogenic debris by marine animals may impact human health," write the authors of the U.C. Davis report. "These concerns have prompted a concerted effort from government and private organizations to assess the impacts of marine debris on human and environmental health."

It's important to note that researchers found the man-made debris in the guts of fish who had swallowed pollution. That means the contaminated fish are most harmful when eaten whole, which is traditional in Indonesia, according to Phys.org.